We are eating more wheat products now than ever before. Damaged gut flora or dysbiosis is also on the rise due to the high usage of antibiotics or consuming food that they can't digest. The immune system may see the undigested gluten particles are a microbial invader and attack them.

Wheat and corn seem to have been identified as the 2 worst as far as chemical spraying and there for higher levels of toxins.

Other than that maybe some more research but I don't think there is much doubt and so the reason I shared.